I have a form, most of which consists of simple cells, check boxes, etc that
are easy for the user to fill out.

However, I need three instances in which an infinite amount of text can be
entered. I tried inserting a Word object, but as the Word file expands, it
spills out over the cells below; I can't designate "X" number of merged cells
as there is no way of knowing how much text to allow for. It may be ten
lines, it may be 100.

What suggestions do you have?